/* fft/gsl_fft_halfcomplex.h
 * 
 * Copyright (C) 1996, 1997, 1998, 1999, 2000 Brian Gough
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#ifndef __GSL_FFT_HALFCOMPLEX_H__
#define __GSL_FFT_HALFCOMPLEX_H__

#include <stddef.h>

#include <gsl/gsl_math.h>
#include <gsl/gsl_complex.h>
#include <gsl/gsl_fft.h>
#include <gsl/gsl_fft_real.h>
#include <gsl/gsl_types.h>

#undef __BEGIN_DECLS
#undef __END_DECLS
#ifdef __cplusplus
# define __BEGIN_DECLS extern "C" {
# define __END_DECLS }
#else
# define __BEGIN_DECLS /* empty */
# define __END_DECLS /* empty */
#endif

__BEGIN_DECLS

GSL_EXPORT int gsl_fft_halfcomplex_radix2_backward (double data[], const size_t stride, const size_t n);
GSL_EXPORT int gsl_fft_halfcomplex_radix2_inverse (double data[], const size_t stride, const size_t n);
GSL_EXPORT int gsl_fft_halfcomplex_radix2_transform (double data[], const size_t stride, const size_t n);

typedef struct
  {
    size_t n;
    size_t nf;
    size_t factor[64];
    gsl_complex *twiddle[64];
    gsl_complex *trig;
  }
gsl_fft_halfcomplex_wavetable;

GSL_EXPORT gsl_fft_halfcomplex_wavetable * gsl_fft_halfcomplex_wavetable_alloc (size_t n);

GSL_EXPORT 
void
gsl_fft_halfcomplex_wavetable_free (gsl_fft_halfcomplex_wavetable * wavetable);


GSL_EXPORT int gsl_fft_halfcomplex_backward (double data[], const size_t stride, const size_t n,
                                             const gsl_fft_halfcomplex_wavetable * wavetable,
                                             gsl_fft_real_workspace * work);

GSL_EXPORT int gsl_fft_halfcomplex_inverse (double data[], const size_t stride, const size_t n,
                                            const gsl_fft_halfcomplex_wavetable * wavetable,
                                            gsl_fft_real_workspace * work);

GSL_EXPORT int gsl_fft_halfcomplex_transform (double data[], const size_t stride, const size_t n,
                                              const gsl_fft_halfcomplex_wavetable * wavetable,
                                              gsl_fft_real_workspace * work);

GSL_EXPORT 
int
gsl_fft_halfcomplex_unpack (const double halfcomplex_coefficient[],
                            double complex_coefficient[],
                            const size_t stride, const size_t n);

GSL_EXPORT 
int
gsl_fft_halfcomplex_radix2_unpack (const double halfcomplex_coefficient[],
                                   double complex_coefficient[],
                                   const size_t stride, const size_t n);

__END_DECLS

#endif /* __GSL_FFT_HALFCOMPLEX_H__ */
